Quartz glass plates with high refractive index homogeneity

Abstract

A method produces homogenous quartz glass plates without streaks. The method is applied to starting quartz glass body which has an X—X geometrical axis and good refractive index homogeneity in its central area, and a refractive index homogeneity decreasing as the axis lies further from a central area. The body is divided into at least two concave parts by longitudinal cuts parallel to the axis once the central area has been processed out of the body. The parts are placed separately in corresponding molds and heated therein such that they are molded to form quartz glass plates having a desired thickness.

What is claimed is:  
     
       1. A method for producing quartz glass plates of high refractive index homogeneities from a cylindrical quartz glass body having a high refractive index homogeneity along its geometrical axis and in circumferential direction, and a variable refractive index curve at least approximately in rotational symmetry to a cylinder axis X—X, comprising: 
       cutting out an interior portion of said cylindrical quartz glass body to form a ring shaped body;  
       separating the ring shaped body into at least two concave parts along separation cuts substantially parallel to the axis X—X;  
       separately inserting said at least two concave parts into corresponding moulds; and  
       heating said at least two concave parts in said moulds such that said at least two concave parts are respectively transformed into quartz glass plates of a desired thickness.  
     
     
       2. Method as claimed in  claim 1 , wherein the separation cuts are angled to defines planes intersecting the axis X—X. 
     
     
       3. Method as claimed in  claim 1  or  2 , wherein a peripheral portion of the cylindrical quartz body extending in direction of the axis X—X is removed before separating to yield the ring shaped body which is separated into the at least two concave parts. 
     
     
       4. Method as claimed in  claim 3 , wherein said interior portion of the quartz glass body is cut out by a hollow drill before said separation of the ring shaped body into said concave parts. 
     
     
       5. Method as claimed in  claim 1  or  2 , wherein outer edges, extending in parallel to the axis X—X, of the concave parts are cut off before inserting said concave parts into the moulds. 
     
     
       6. Method as claimed in  claim 1 , further comprising forming optical components from said concave parts, wherein each of said optical components has an optical axis O—O directed at least substantially at right angles to the axis X—X. 
     
     
       7. The method as claimed in  claim 3 , wherein outer edges, extending in parallel to the axis X—X, of the concave parts are cut off before inserting said concave parts into the moulds. 
     
     
       8. The method as claimed in  claim 7 , further comprising forming optical components from said concave parts, wherein each of said optical components has an optical axis O—O directed at least substantially at right angles to the axis X—X. 
     
     
       9. The method as claimed in  claim 3 , further comprising forming optical components from said concave parts, wherein each of said optical components has an optical axis O—O directed at least substantially at right angles to the axis X—X. 
     
     
       10. The method as claimed in  claim 4 , wherein outer edges, extending in parallel to the axis X—X, of the concave parts are cut off before inserting said concave parts into the moulds. 
     
     
       11. The method as claimed in  claim 10 , further comprising forming optical components from said concave parts, wherein each of said optical components has an optical axis O—O directed at least substantially at right angles to the axis X—X. 
     
     
       12. The method as claimed in  claim 7 , further comprising forming optical components from said concave parts, wherein each of said optical components has an optical axis O—O directed at least substantially at right angles to the axis X—X.